Israeli forces have arrested 100 people at Gaza’s largest functioning hospital amid mounting fears for patients and staff trapped inside, as airstrikes across the Palestinian territory killed dozens more people. At least 120 patients and five medical teams were trapped without water, food and electricity in the Nasser hospital in the southern city of Khan Younis, according to the health ministry in Gaza. “Newborn children are at risk of dying in the next few hours,” the ministry warned on Saturday. It added that troops had turned the hospital into a “military base” and detained “a large number” of medical staff after raiding the complex on Thursday. It came as the bombardment of Gaza continued overnight with another 100 people killed in Israeli strikes, according to Agence France-Presse (AFP), which cited the Hamas-run health ministry. Witnesses said explosions were heard at dawn in the southern Gaza town of Rafah, where about 1.4 million displaced civilians are sheltering. Israel’s bombardment and ground invasion of Gaza since Hamas’s 7 October attacks have displaced more than 85% of the population, with many taking refuge in a makeshift encampment by the Egyptian border. Intense fighting raged last week around the Nasser hospital – one of Gaza’s last remaining operational medical facilities. The Israel Defence Forces (IDF) said troops entered the hospital on Thursday, acting on what it said was “credible intelligence” that hostages seized on 7 October had been held there. The UN criticised the raid while medical staff reported on Thursday that the hospital was hit directly by tank fire. The power was cut and the generators stopped after the raid, leading to the deaths of six patients due to a lack of oxygen, according to the health ministry. It was feared that Dr Khaled al-Serr, a surgeon at the hospital who had continued working during the raid, was among those detained. A team of international doctors on Saturday said that they had lost touch with him 33 hours before. In his last update, al-Serr told how an ICU patient had died because of the lack of electricity. “Even as the Israeli military invaded Nasser hospital, Khaled continued sending us updates from the ICU,” the doctors said in a statement. The IDF said on Saturday that it was continuing to conduct “a precise and limited operation against the Hamas terrorist organisation within the Nasser hospital”. It said it had detained 100 people suspected of “terrorist activity”. Israel’s defence minister has said that at least 20 of those held had been involved in the 7 October attack. Israel has for weeks concentrated its military operations in Khan Younis, the home town of Hamas’s leader, Yahya Sinwar, the alleged architect of the 7 October attack in which about 1,200 people were killed and another 250 abducted. At least 28,858 people, mostly women and children, have been killed in Israel’s subsequent assault on Gaza, according to the health ministry. More than 68,000 people have been wounded, including 11,000 who need urgent evacuation for treatment outside Gaza, it added. It is thought 130 hostages are still in Gaza, including 30 presumed dead, according to Israeli figures. Meanwhile, G7 foreign ministers, meeting at the Munich Security Conference, expressed their “deep concern about the potentially devastating consequences of a large-scale Israeli military operation in Rafah”. Although western leaders have been issuing statements for days either individually or bilaterally urging Israel to show constraints, this is the first time the G7 group has issued such a clear joint warning to Israel. There are reports that Israel may not have sufficient troops to launch a full ground offensive for some weeks, but western diplomats said Israel believes it has a credible plan that can defeat Hamas in Rafah while the population sheltering in refugee camps is transferred within Gaza. The west is insistent the loss of life will probably be unacceptable. Antony Blinken, the US secretary of state, relayed the message from the G7 to the Israeli president Isaac Herzog, who came to Munich with the families of hostages. High-level negotiations to pause the war were held in Cairo last week but their outcome is unclear. The talks are focused on how many prisoners will be released proportionately for the release of each Israeli hostage. The discussions are hampered by the difficulties in maintaining contact with Hamas chief Yahya Sinwar in Gaza. Hamas’s political bureau head, Ismail Haniyeh, said on Saturday that the Palestinian resistance would “not accept anything less than a complete cessation of Israeli aggression”. In Munich, Blinken tried to set out the opportunities for Israel if it struck a deal. There is an “extraordinary opportunity” in the months ahead for Israel to be integrated into the Middle East as Arab countries are willing to normalise ties with the country. Blinken also highlighted the “urgent” imperative to proceed with a Palestinian state that would also ensure the security of Israel. Earlier, China’s foreign minister, Wang Yi, called for a ceasefire and an “accelerated state of Palestine”.